The variety of multi-conductor cables including those that have different connector types terminating the ends have virtually an unlimited combination of connector pin connections or combinations, and thus cannot be quickly or rapidly tested to determine their continuity without reference to specific cable data. Furthermore, the proliferation of complex equipment to be interconnected makes cable verification an increasingly recurrent task. Moreover, identification of the particular cable function or interconnect is necessary to determine the corresponding pin connection information, which determination is frequently unavailable or time consuming to provide.
A great many modern computer cables do include internal wiring. Worse, the internal wiring is sealed in molded connectors that are identical in appearance to other cables that have different internal wiring. Thus, it is impossible to differentiate certain cable types by appearance only. As a consequence, many cables that look right for an application and fit everything properly do not work, leading to confusion, tedious debugging, and possible ascribing the fault to a computer or peripheral to which the cable connects, in turn leading to disassembly of the computer or peripheral In addition to wasted time, damage may be done to the unnecessarily-opened equipment in attempting to solve the problem.
Cables also occasionally incorporate particular electronic components, such as diodes, at the connectors to provide a form of equipment interface or adapter to permit communication between equipment not originally intended. Such electronic components are inadequately detected or measured by existing cable testers which typically interrogate the data path by placing interrogation signals only on one connector and receiving signals from the second connector. Since cables having direction related continuity will provide different continuity depending on which connector the interrogation signal is applied and the direction or polarity of the interrogation signal. Thus, cable testers adapted to perform continuity measurements on some cables will provide incomplete or erroneous findings.